Ren'Py Visual Novel Engine

Ren'Py is an engine that supports the creation of visual novels and dating sims, forms of computer-mediated storytelling. It supports a movie script-like syntax that makes creating simple games easy, while still being customizable and extensible by advanced creators. With no additional work by the game-maker, it supports features expected of all visual novels, like loading, saving, preferences, and rollback.

RenPyTom
(renpytom)

Ren'Py is an engine that supports the creation of visual novels and dating sims, forms of computer-mediated storytelling. It supports a movie script-like syntax that makes creating simple games easy, while still being
customizable and extensible by advanced creators. With no additional work by the game-maker, it supports features expected of all visual novels, like loading, saving, preferences, and rollback.

Ren'Py is based on on pygame, and uses Python to allow visual novels to contain reasonably complex logic.

Ren'Py is open-source software, and is free to use for commercial and non-commercial purposes. Ren'Py is supported on Windows, Mac OS X, and Linux, and can be made to run on other platforms.